This system relates to television jamming systems and more particularly relates to systems for encoding and decoding television transmissions for subscription TV.
The need for practical systems offering security for pay TV has become increasingly apparent. Both active and passive systems have been developed and are marketed at present which are designed to prevent non-subscribers from watching pay TV premium channels. Some of the accepted systems include trapping at the pole, converters, switchable taps, and various encoding-decoding systems. In general, the cost of these systems is directly proportional to the degree of security they offer. It seems fair to say, however, that there is no fully secure system and the present systems have not achieved wide acceptance. Still, it remains necessary to secure pay TV transmissions to some extent in order to make pay TV a realistic business proposition.